Women are twice as choosy as men when they go speed dating, research suggests. Why might that be?

Trying to work out who is single in a bar, approach them and asking them out before you know anything about them is not a very efficient way of finding a girlfriend or boyfriend.

There is a solution - speed dating, where a group of singles meet at an event in a bar or cafe. The men move from table to table for a fleeting date with each woman, lasting typically between three to four minutes.

Afterwards the participants tell the organisers, often online, which people they want to see again.

A recent study into speed dating habits concluded that if men and women go to an evening and have 22 separate dates, men are keen to see about five women again, while women would only choose to see two again, on average.

That means that for every offer a woman makes, she has roughly a 50-50 chance that the man will want to see her again too.

But for every offer a man makes, he only has a one in five chance that the desire to meet again is reciprocated.

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The research was done by economists Michele Belot from the University of Edinburgh and her colleague Marco Francesconi from the University of Essex, who collected data from 84 speed dating events involving 3,600 people in the UK.

This controlled environment is something that excites some economists as they are perfect for observing market forces at work- in this case the dating market.

But why are men less fussy?

"This is something that evolutionary psychologists and biologists do recognise," says Belot. "We know that across a whole range of behaviours women tend to take fewer risks.

"They relate this to the fact that making mistakes are much more costly for women than for men because of childbearing. So obviously if you make a mistake in dating the wrong man and having a relationship with the wrong man, you might have nine months carrying a child, then caring for a child. While for men, the costs are lower."

Other academic work suggests that because men historically have not been so involved in parenting, they devote more time to "short-term mating", so they're not looking further than a date.

A study in the US, on the other hand, suggests the difference might simply be down to the seating arrangements, because the convention is for women to sit still at the events, while men move round and approach each woman.

The researchers found that when the roles were reversed at speed dating events, and women moved round to approach the men, they found that women made more offers than they did at events when they sat still. One possible theory is that the person who moves has more confidence.

Belot and Francesconi's study also took all the data provided by each person from their profile, to work out what attributes people were looking for in a potential mate.

"For both men and women, education and professional status matters. We found that women prefer taller men and men prefer slimmer women," says Belot.

Perhaps this is not a big surprise. But it turns out - people are often ready to compromise on these preferences.

So, if a woman likes academic men, but she goes speed dating one night and no one is particularly academic, she will lower her expectations on this occasion, and instead pick men who next best fit her criteria.

Belot thinks one explanation is that people who go to a speed dating event assume that is representative of the pool of available single people.

But if you break out of the mould of what you think you want, it could actually be beneficial for society at large.

People marry people very similar to themselves - from the same socio-economic background for example. And economists argue that this stops social mobility between generations.

For instance, people from rich privileged backgrounds marry each other, while people from more disadvantaged backgrounds marry each other.

But speed dating shows that people are not too fixed in their views of who they should date, says Belot, if they are given the opportunity.

"It's interesting to see [with speed dating] it gives a bit of hope that if you do mix people, they do tend to mix."